1. Technical Field
This invention relates to a rotation transmitting device for transmitting a drive force such as a rotational force between different working environments which are airtightly divided by a partition wall.
2. Description of the Prior Art
In the field of semiconductor manufacturing equipment, for example, a vacuum pump is used to maintain a reaction chamber a high vacuum condition, in which wafers are disposed and reaction gasses are introduced to form thin films on the wafers by means of CVD or other method. Work transfer in the reaction chamber must be carried out while maintaining an airtight condition, and a transfer mechanism therefor must be constituted so that an arm portion for gripping works in the reaction chamber is partitioned in a perfectly airtight condition from a drive mechanism for transmitting a drive force to the arm portion from the outside of the reaction chamber. Further, dust or the like must be prevented from generating as much as possible at the side of the reaction chamber. Therefore, it is preferable that the drive mechanism for driving the arm portion in the reaction chamber does not generate wear particles, lubricant mist or the like.
In the past, as a mechanism for transmitting a drive force from one to the other side between different working areas which are perfectly partitioned with each other, there have known one that has magnet couplings, one that has bellows, and one that has magnetic seals. On the other hand, the assignee of this patent application proposed a rotation transmitting device that utilizes a flexible meshing type gear drive in Japanese Utility Model Laid-Open No. Hei 1-116798.
The rotation transmitting device utilizing the flexible meshing gear drive is capable of transmitting a rotational force of high torque between partitioned working areas with high rotational accuracy.
An object of this invention is, in a rotation transmitting device utilizing a flexible meshing type gear drive, to realize lubrication to portions of the rotational transmitting device that must be lubricated appropriately for a prolonged period of time, whereby realizing prolongation of the life of the rotation transmitting device.
Further, another object of this invention is to provide a mechanism for suppressing generation of wear particles and other dust in a rotation transmitting device utilizing a flexible meshing type gear drive.